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-   -   Quality comparison of 24p and 60p (https://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/118882-quality-comparison-24p-60p.html)

Jad Meouchy April 8th, 2008 11:02 AM

Quality comparison of 24p and 60p
 
Does anyone have any image quality comparisons of 24p and 60p? I bought the 200U to switch to 60p, but I am a bit disappointed at the visual quality of my final pictures. I am almost certain my HD100 looks better at 30p than my HD200 at 60p. 'Better' of course is an ambiguous term; in this case, it references noise and encoding artifacts.

Aaron Winters April 8th, 2008 11:07 AM

I have a simple, non-scientific, shot in the backyard test I could throw up tonight or tomorrow.

If you have some footage throw it up so we can see what your working with. Would like to see the HD100 30p stuff.

Jad Meouchy April 8th, 2008 11:14 AM

I'll put up png grabs tonight. To be fair, the conditions were stressing the codec (60p, 1/250th, lots of bg detail, single color high-speed moving objects), but I really expected better performance than I got; the artifacts are comparable to a consumer dvcam. I'm wondering if I should have shallowed up the dof to reduce the data needed for the bg pattern.

Justin Ferar April 8th, 2008 12:30 PM

Jad,

The severe macro blocking in JVC's HDV 720p60 hasn't really been reported up to this point.

After shooting a full year and a half I too have been most disappointed with the codec. The image really falls apart during sudden changes. All you have to do is point the camera at a bush and swipe your hand in front of the lens. Then look at the results frame by frame in post and you will see the poor results of the long GOP method.

So yes, 720p30 mode (which has a shorter GOP) actually performs better than 720p60 during scenes with a lot of movement- effectively negating the whole purpose of 60 fps.

Now I wish I had bought two HD250's instead of two 200's as that SDI out suddenly becomes extremely relevant.

Jad Meouchy April 8th, 2008 01:00 PM

This is what I was afraid of.

I'm hoping JVC may announce something at NAB to remedy this situation. I believe the lens and ccd are more than sufficient for my purposes for the next 12 months, but the macroblocking at 60p (my target framerate) is becoming a dealbreaker.

Mark Silva April 8th, 2008 03:51 PM

wow.

and all that talk of how much better the blue channel is on the super encoder had me rethinking my HD100 purchase.

I'll stick with what works.

Justin Ferar April 8th, 2008 04:43 PM

If your testing the blue channel by shooting a chart or a still scene then yeah, it looks totally amazing. It's when you start running and gunning that all the macro blocking occurs. Photo flashes in particular completely destroy the image for about three frames thereafter.

The 720p60 HDV codec is more than adequate for well lit talking heads and talk show style interviews- in fact would be nearly impossible to improve upon.

Adam Letch April 8th, 2008 07:03 PM

Yup the 50/60p is only good
 
on static objects, which is not obviously its intended target, shot a whole 2 day equine event with it and never again, 25p with a higher shutter speed for me from now on. And if you do, make sure your nle is good with it, I used Vegas 8.0b and it sucks with 50p, if I exported as anything other than a 50p uncompressed AVI, and then reimported it back into DVDA as a 25pSD project, it would have like a ghost effect on the image and was unusable, at one point I thought I'd have to buy a new NLE just to do the job, but after much pain and aingst mucking around I got it to work. It meant a 10Gb per minute of footage render.
The 50/60p though will mean something when the convergent design is released, I think this is truly the next biggest advancement in the prosumer video market, my 251 with 4:2:2 uncompressed audio at multiple bit rates. Then the 50/60p would also be National Geographic friendly ;-P

Jad Meouchy April 9th, 2008 01:44 AM

Here are a few stills:
http://www.metrofilmclub.com/i/cks08

http://www.metrofilmclub.com/i/cks08...09_mrdirty.png
is the worst

Shaun Roemich April 9th, 2008 08:47 AM

Yep, those are bad, indeed. To be fair, though, how does 60p look IN MOTION? Could you Vimeo a short clip or two so we can take a real look?

Bill Ravens April 9th, 2008 09:08 AM

I've had very similar experiences with my HD110. I shoot a lot of panoramic views, outdoors. Background vegetation has a high degree of detail, trees and bushes. Combine the high level of detail with panning motion and the GOP encoding falls on its face. In these cases, I've found I dislike the motion blurring, as it looks worse. Shooting with a shutter speed of 125 helps, going to 250 improves the issue even more. Of course, the cadence is lost, but, that's a far smaller visual penalty than the macroblocks you've seen.

Eric Gulbransen April 9th, 2008 09:32 AM

I put this together a while ago. May be interesting here:

http://www.dvinfo.net/conf/showthread.php?t=102198

Shaun Roemich April 9th, 2008 10:07 AM

Thank you so much!

Not sure what to think... the rippling of the shirt looks unnatural (almost as if it runs in reverse) in EVERY clip. Maybe I'm still too interlaced. Decisions, decisions...

Mark Silva April 9th, 2008 05:42 PM

Quote:

Originally Posted by Jad Meouchy (Post 856860)

Mr. Clean and Mr Dirty both look the same to me.

Jad Meouchy April 9th, 2008 05:48 PM

mrclean is an I-frame
mrdirty is not

you'll have to zoom in to notice it


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